High film strength lubricant compositions



Patented May 24, 1938 UNITED STATES PATENT orrics HIGH FILM STRENGTH LUBRIG COMPOSITIONS William J. Marsh and Joseph A. Spine, Niagara Falls, N. Y., assilnors to Hooker Electrochemical Company, New York, N. Y., a corporation of New York No Drawing. Application June 5, 1936,

Serial No. 83,731

9 Claims. (01. 87-9) It is known that various halogenated and more The particular merit of our low solidification point particularly chlorinated hydrocarbons, when chlor-benzene is that it has a satsifactory soluadded to mineral lubricating oils, have the propbility without being volatile. erty of increasing film strength. Among the We have now discovered that many other available hydrocarbons, those of the aliphatic chlorinated hydrocarbons form not only low solidseries, when chlorinated, have good film strengthification point mixtures, but in some cases true ening properties and are very soluble in or miacieutectics, not only with tne chlor-benzene but 1116 with lubricating Oils- These chlorinated with each other. It seems to be a further char- Phatic hydrocarmns are, however, not Sumcient' acteristic that low melting temperature is a con- 10 stable fmwuse under high temperature comitant of high solubility in mineral oils. We tions, such as those met with in automobile crank shall refer to these mixtures as high solubility cases. Under such conditions the chlorinated mixtures", it being understood that by this aromatic hydrocarbons are preferred on account pressmn is meant mixtures of chlorinated hydr of their greater heat stability These latter a carbons of high solubility in mineral oils relative is however, in general, a relatively low solubility in t m 1 mm 1 th t 1th ixt mineral lubricating 0113, a circumstance which 0 y o e componen so em limits the percentage of chlorine which can be Thus we have found that tetrachlor-benzene as introduced into the on in combination with these well as our low solidification point chlor-benzene materiala form such low-melting, high-solubility mixtures Among the chlorinated aromatic hydrocarbons with p a n a. c l -d n ny s. and

that have been used are chlor-naphthalenes and y other Chlorinated. y fl fl chlor-diphenyls. These materials, besides hav- The following table gi s he mel in p n ing a limited solubility, are open to the further various mixtures of the material described:

I Melt- Melt- Melt- Component ing Percent Component ing g ing point age P in 5 Point C. C. C'. Chlor-naphthaleno 128 75- 'letrachlor-bennene 138 25 84 Chloe-naphthalene 128 50- L. S. P. chlor-benzene 94 50 62 Ohlor-dipbenyl 163 L. S. P. chlor-benzene 94 65 78 1 56% chlorine. I 68% chlorine.

objection that they are expensive. The chlor- In the foregoing table the proportions given benzenes are satisfactory from the point of view approximate those which give the lowest melting of cost, but for various practical reasons only the points. With a little more care in determining tetrachlor and hexachlor have hitherto been the critical proportions, it is believed that true available and these are unsatisfactory from the eutectics could be obtained. However, we do not point of view of solubility. In co-pending appli wish to be limited to eutectic mixtures since any cation Serial No. 76,661 filed April 27, 1936 we increase in solubility is a useful result. Morehave disclosed a process for production of a over, in incorporating these waxy chlorinated special mixture of chlor-benzenes which is charhydrocarbons with mineral lubricating baseoils acterized not only by a low melting temperature it is customary, if not practically necessary, to but also by high solubility in lubricating oils. raise the temperature of the oil above the melting This mixture is not a blend but is naturally point of the waxy hydrocarbon. The relatively formed during the process of chlorination and low melting point of our mixture therefore greatconsists principally of the isomers of tetrachlor ly facilitates the blending of these materials with benzene, together with pentachlor and hexachlorthe base oils. Thus, it will be seen that in every benzene. It is not a eutectic but is mushy over case the melting point of the mixture is from a range of several degrees. We therefore call it 40 C. to 120 C. lower than that of either comour "low solidification point chlor-benzene or ponent and well below the temperature of low L. S. P. chlorbenzene". While monochlorpressure steam. These temperatures are therebenzene and some of the isomers of dichlorand. fore very much easier to.attain in the oil refinery trichlor-benzene are of satisfactory solubility than those which have heretofore been necessary these are too volatile to have any practical value. in blending high film-strength lubricants.

The limit of solubility of these film-strengthening agents in oils is considered to be the percentage that remains in solution at 0 F. or that redissolves when the oil is brought back to room temperature. The solubility of the various mixtures mentioned above, as determined in this Way, in mineral lubricating oil having a Saybolt viscosity of 230.seconds at 100 F. is as follows:

\ By weight, in 230 100 F., oil, based on the oil.

It will therefore be seen from the above table that through our invention the percentage of chlorine that may be introduced into lubricating oils in chemical combination with aromatic hydrocarbons may be more than doubled. At the same time, because of the relative cheapness of the materials that are thus made available, the cost of the lubricant may be reduced. This greatly widens the scope of usefulness of such compounds. Moreover, by means of such combinations as those described above and others too numerous to mention, the technical properties of the lubricant itself may be improved. Thus, the eutectic mixtures, by increasing the available chlorine content, not only raise the breakdown point of the lubricant, but lengthen its useful life.

We do not wish to be limited to the specific materials listed, as it is obviously impossible to discuss all the possible chlorinated hydrocarbons which in various combinations will form useful mixtures of low melting point and high solubility.

Wherever in the claims the word solid occurs, it is to be understood that solid at the upper limit of atmospheric temperature is meant. Whenever the solubility in mineral oil is given, it

is to be understood as having been determined by.

the freeze test hereinbefore described. In the claims the expression simple carbon ring struc ture is intended to exclude carbon ring compounds complicated by side chains, such as aliphatic groups, which affect the solubility and heat-stability of the compound, also those having oxygen groups, which are not considered to be hydrocarbons. The expression non-volatile means non-volatile for practical purposes under the conditions of use in the crank case of internal combustion engines.

Although only mixtures of two components have been considered, it will be obvious that three or more components could be used.

We claim as our invention:

1. An addition agent of relatively low melting point and high solubility in mineral lubricating oils, which when added to such oils in minor proportion has the property of greatly increasing the oil-film strength thereof, comprising a substantially eutectic mixture of substantially neutral and non-volatile, solid, oil-film strengthening halogenated hydrocarbons of simple carbon ring structure having relatively high melting points and low solubilities in said oils.

2. An addition agent of relatively low melting point and high solubility in mineral lubricating oils which when added to such oils in minor proportion, has the property of greatly increasing the oil-film strength thereof, comprising a substantially eutectic mixture of substantially neutral and non-volatile, solid, oil-film strengthening chlorinated hydrocarbons of simple carbon ring structure having relatively high melting points and low solubilities in said oils.

3. An addition agent of relatively low melting point and high solubility in mineral lubricating oils, which when added to such oils in minor proportion has the property of greatly increasing the oil-film strength thereof, comprising a substantially eutectic mixture of substantially neutral and non-volatile, solid oil-film strengthening chlorinated hydrocarbons of simple carbon ring structure having relatively high meltin points and low solubilities in said oils, at least one of said chlorinated hydrocarbons having a greater solubility in said oil as a part of said mixture than by itself.

4. An addition agent of relatively low melting point and high solubility in mineral lubricating oils, which when added to such oils in minor.

proportion has the property of greatly increasing the oil-film strength thereof, comprising a substantially eutectic mixture of substantially neutral and non-volatile solid chlor-naphthalene and tetrachlor-benzene having relatively high melting .points and low solubilities in said oils.

5. An addition agent of relatively low melting point and high solubility in mineral lubricating oils, which when added to such oils in minor proportion has the property of greatly increasing the oil-film strength thereof, comprising a substantially eutectic mixture of solid chlor-naphthalene and chlor-benzenes above trichlor-benzene having relatively high melting points and low solubilities in said oils.

6. An addition agent melting at substantially 84 C. and having a solubility of substantially 12% in mineral lubricating oil of 230 seconds Saybolt viscosity at 100 E, which when added to mineral lubricating oils has the property of greatly increasing the oil-film strength thereof, comprising a mixture consisting substantially as to 75% of chlor-naphthalene melting at about 128 C. and having a solubility of about 9% in said oil and as to the remainder of tetrachlorbenzene melting at about 138 C. and having a solubility of about 2% in said oil.

'7. An addition agent melting at substantially 62 C. and having a solubility of substantially 18% in mineral lubricating oil of 230 seconds Saybolt viscosity at 100 F., which when added to mineral lubricating oils in minor proportion has the property of greatly increasing the oil-film strength thereof, comprising a mixture consisting substantially as to 50% of chlor-naphthalene melting at about 128 C. and having a solubility of about 9% in said 011 and as to the remainder of a mixture of tetrachlor-benzene isomers, pentachlor-benzene and hexachlor-benzene melting at about 94 C. and having a solubility of about 7% in said oil.

8. A solid addition agentof relatively low melting point and high solubilityinminerallubricating oils which when added to such oils in minor proportion has the property of greatly increasing the oil-film strength thereof, comprising a substantially eutectic mixture of substantially neutral, solid chlor-dlphenyl and chlor-benzenes above trichlor-benzene having relatively high melting points and low solubilities in said oils.

9. An addition agent melting at substantially 78 C. and having a solubility of substantially 11% in mineral lubricating oil of 230.seconds Saybolt viscosity at 100 E, which when added to mineral lubricating oils in minor proportion has the property of greatly increasing the oil-film 10 strength thereof, comprising a mixture consisting substantially as to 35% of chlor-diphenyl melting at about 163 C. and having a solubility of about 7% in said oil and as to the remainder of a mixture of tetrachlor-benzene isomers, pentachlor-benzene and hexachlor-benzene, melting at about 94 C. and having a solubility of about 7% in said oil. 4 

